ES2230364T3 - DRIVING DEVICE FOR A TOOL TENSIONER OR FOR WORK PARTS IN A SPINDLE OF A MACHINE-TOOL. - Google Patents

Abstract

The invention relates to an actuating device for a tool or a workpiece tensioning jack in a machine tool spindle. The actuating device includes a pressure piston which is arranged inside a housing for actuating the tool or workpiece tensioning jack. In order to provide a compact, space-saving actuating device enabling leakage fluid to be drained off in a simple manner, several interspaced continuous bores are arranged concentrically around a center axis in a side wall of the housing. Pressure plungers which are axially displaceable with the aid of the pressure piston are disposed therein and the housing contains at least one leakage channel with a section extending between the pressure plungers in a radially outer direction.

Description

Drive device for a tensioner for tools or for work pieces in a spindle of a machine tool.

The invention relates to a device of drive for a tool tensioner or for a piece of work on a machine tool spindle according to the preamble of claim 1.

The working spindles of machine tools or machining centers normally have an integrated tool tensioner for automatically tension and release the machining tools. In the case of conventional tool tensioning devices, the tools are normally tensioned by a clamp tensioner that is arranged at the front end of a bar tensioner presented by means of a disc spring package and that acts directly on a corresponding tightening bolt of the tools or tools tensioning devices. To release the tools, the tension bar is moved by means of a piston-driven cylinder unit normally hydraulically against the clamping force of the disc spring package, so that the clamp mandrel is Open and release the tool. Additionally it is also provided an internal supply of cooling medium, in which The refrigerator lubricating medium can be driven to the tool, for example by means of the tension bar made hollow through the inside of the work spindle. To do this, without However, the refrigerator lubricating medium must be guided by means of a suitable device from a connection piece stationary to the parts that rotate in machining. This takes normally carried out by means of the so-called turning steps, in those that pass between the fixed parts and the rotating parts are carried out by means of sealing rings that slide one over the other. To get a construction mode that saves space and make it particularly compact, the turning step can be integrated inside the drive device for the tool tensioner. Since, however, this type of turning steps are not completely sealed, and it produces, especially at the junction point between your pieces stationary and their rotating parts, a leak from the middle Lubricant refrigerator, the problem occurs, especially in the case of a compact construction mode, of an extraction adequate leakage fluid.

From document DE 19543612C1 a known generic drive device for a tool tensioner or work pieces, which contains a pressure plunger arranged inside a housing to drive a bar prestressed traction by means of a spring package. In this drive device is integrated a turning step, which it contains a first sliding disc fixedly connected with the pull bar, and a second sliding disc arranged in a special sealing piece. The pressure plunger made as an annular piston is housed in a cylinder that is guided by so that it can move axially in a fixed part of the machine. When the annular piston is requested with pressure inside the cylinder, then the piston is supported by means of elements hook the inner part into the spindle, and exerts a force corresponding opposite on the cylinder that can move axially The drawbar and also the turning step are dragged by this one.

The aim of the invention is to achieve a compact and space-saving drive device of the type mentioned at the beginning, that makes possible a simple extraction of the leakage fluid

This objective is achieved according to the invention. by means of a drive device with the characteristics of claim 1.

Through the arrangement distanced from each other of the diver plungers, a space for the realization of one or more drills or leakage channels, to which backpressure free leakage fluid can flow, and it can be collected there or it can be extracted through pipes corresponding. In particular, in the vertical position of a spindle of a machine tool, the liquid of leaks flows by itself down, and in case it is necessary, it can be extracted at corresponding intervals, or well it can be constantly transported by means of pipes adequate. The drive device according to the invention it presents a particularly compact construction form, and by this is also indicated in particular for machine tools with a reduced supply of space.

The subordinate claims indicate suitable configurations and advantageous variants of the invention.

Thus, the housing contains, in a simple implementation from a constructive and cheap point of view, an inner part of the housing and an outer part of the housing fixedly connected with it, by means of which a annular pressure space for the pressure plunger. He leakage channel is properly shaped by means of drills that run parallel or perpendicular to the axis central housing. Drills may be closed in their ends open out by means of closure plugs or locking screws, or may be connected to pipes corresponding drain.

Inside the housing of the device drive is provided a turning step for feeding a working and / or cleaning fluid for the spindle of the tool-machine that rotates in operation. The turning passage is properly housed in a special housing, and thanks to that it can be assembled and disassembled in a way simple.

In the drive device housing, an air supply channel may also be provided for the Cleaning of tensioning surfaces or similar.

Other peculiarities and advantages emerge of the following description of a preferred embodiment example a Start drawing. It shows:

Figure 1 a part of the tool tensioner with a drive device according to the invention in section;

Figure 2 a side view of the device drive shown in Figure 1;

Figure 3 a sectional view of the device drive in an offset section plane with respect to the Figure 1 and

Figure 4A, 4B a diver plunger assembly in the pressure plunger

A part of a tensioner is shown in Figure 1 for tools 2 mounted on a spindle of a machine tool 1 and a device drive 3 with a so-called turning step 4 for the feeding a working and / or cleaning fluid to the spindle of the machine tool 1. The parts represented of the tool tensioner 2 and the drive device 3 are shown in the upper half of Figure 1 in a position loose and in the lower half in a tense position.

As shown in Figure 1, the drive device 3 contains a cylindrical housing hollow, which is formed by an inner part of the housing 5 and an outer part of the housing 6 fixedly bolted with is. By means of the inner and outer part of the housing 5 and 6 a sealed pressure space 9 is limited by means of seals 7 and 8, in which a pressure plunger is arranged 10 so that it can move in the axial direction of the Case. The pressure plunger 10 is sealed by means of sealing element 11 and 12 interior and exterior with respect to the inner and outer wall of the pressure space 9 annularly. In the front part 13 of the pressure plunger 10 directed to the tensioner for tools the inner ends of several are fixed cylindrical diver plungers 14 spaced apart with the same angle in the contour direction, whose other ends protrude outward of the housing in the upper half of the loose position depicted in Figure 1. Diver plungers 14 are arranged in several through holes 16 arranged concentrically around a central axis 15 of the housing in a radial flange 17 formed in the part of the housing 5, which forms a wall side of the housing. Additionally, diver plungers 14 are sealed by means of suitable sealing rings 18 in the radial flange 17 relative to the housing, and are guided so that can be moved axially in guide holes 19 corresponding of a guide ring 20 arranged inside of the pressure space 9.

The housing part 5 provided with an opening central step 21 contains several leakage channels 22, which carry from an annular groove 23 in the inner wall of the opening of step 21 to a drain opening 24 closed by means of a screw 46 on the outer contour of the radial flange 17. The channel of leaks 22 is formed by means of a section 25 that runs in the radial flange 17 transversely with respect to the central axis 15 between two plungers radially outward towards the opening of drain 24 and through a section 26 that forms a right angle with it, which runs parallel to the central axis 15 between the inner wall of the passage opening 21 and the pressure space 9. Suitably, the leakage channel 22 is constructed by means of drills that are introduced by the rear front and the outer part of the housing part 5 and that are closed by middle of a closure cap 27 or a screw 46. In the section 25 opens another drain hole 28 at the front of the radial flange 17, which can also be closed by means of a closing screw.

On the contour wall of the outside of the housing 6 is provided a first radial opening of feed 29 leading through a drill 30 to one end back of the pressure space 9 annularly. Through this  feed opening 29 the pressure plunger can be requested 10 ring-shaped with hydraulic fluid as a pressure medium for the output of the plunger diver 14. From a second radial opening of feed 31 in the housing part 6, a drill of power supply 32 running parallel to the axis central 15 leads to the front end of the pressure space 9. By middle of the feed opening 31 and the drill hole supply 32 can be requested with hydraulic fluid the plunger pressure 10 for the plunger inlet 14.

By means of diver plungers 14 driven by middle of the pressure plunger 10 moves a pressure disk 33 which is fixed at the rear end of a tension bar 34 provided with a step drill. The tension bar 34 is arranged inside work spindle 1 so that you can axially displace, and is prestressed by means of a package of disc spring 35 indicated schematically in position tensioner represented in the lower half of Figure 1. In this position, a tool inserted in the tool spindle it is introduced, for example, by a tension clamp not shown, in a cone. To release the tool, the pressure plunger 10 through the first radial opening of feed 29 and drill 30 with a pressurized fluid, in which this, together with the plungers 14, moves from the tension position represented in the lower half of the drawing of the Figure 1 to the loose position represented in the upper half of the drawing. In this case, the tension bar 34 moves through of the pressure ring 33 according to Figure 1 to the left, compressing the disc spring pack 35. Thanks to that, the tensioning clamp arranged at the front end of the bar Traction also releases the tool.

To tension the tool, it is requested with fluid pressurized the pressure plunger 10 by means of the second opening radial feed 31 and feed drill 32, in where the pressure plunger 10 will stop again from its position release to its tense position, and tension bar 34 is retracted to the Working spindle under the effect of disc spring package 35. In this case, a tool inserted in the spindle of the tool by the tensioning clamp does not shown.

Turning step 4 is inserted in the opening of step 21 central. This contains a connection part 36 stationary for the connection of a fixed supply pipe, as well as a rotating joint support 37, which is attached tightly and can be moved axially with a hollow piece of connection 38. The hollow connection piece 38 is screwed into the drill hole of the tension bar 34. From the housing of the passage Turn 4 carries a radial leakage bore 39 outward, which is attached to the annular channel 23. By means of this leakage hole and from the leakage channel 22, the leakage fluid can be extracted from the inside of the turning passage 4 towards the outside.

As can be seen in Figure 2, in the embodiment shown is provided with eight plungers 14 arranged coaxially with respect to the central axis 15 of the housing, and four leakage channels 22 displaced 90º from each other, respectively, each of them with a drain hole 28 in The front part. The number of diver plungers 14 and channels Leakage 22 can, however, be modified in an arbitrary manner. Four through holes 40 are provided on the outside each of them for a screw 41 shown in Figure 3, for means of which the housing can be fixed on the head of the spindle or similar. An additional figure is shown in Figure 3 feed channel for a cleaning fluid, which contains a feed opening 42 arranged radially in the part outside of the housing 6 and a feed hole 43 which runs parallel to the central axis 15, as well as a radial hole 45 in the inner part of the housing 5 which is in contact with it and which flows through a drill oblique feed 44 on the inner wall of the passage opening 21. Through this feed channel you can enter, for example, cleaning air to clean the tension surfaces or similar.

Figures 4A and 4B show the assembly of the plungers 14 on the plunger 10. The plungers 14 cylindrical presented for this at their ends opposite the plunger pressure 10 two lateral flattening 47 opposite each other to the introduction into corresponding "T" shaped slots 48 at the front of the pressure plunger 10 oriented to the diver plungers 14. In this way, diver plungers 14 can be inserted, by means of a simple displacement in direction radial, in the corresponding "T" slot 48, such and as shown in Figure 4A. In the mounting position represented according to Figure 4B, the plungers 14 are fixed then in a simple way in axial direction with respect to the plunger of pressure 10. This way it is achieved with a cost of reduced manufacturing a quick and easy assembly of the pistons diver in the pressure plungers.

The invention is characterized by a way of very compact construction that makes possible a construction that requires little space from a tool tensioner that can be automatically actuate on a spindle of a machine tool.

However, the invention is not limited to represented embodiment example. It can be used in a way corresponding, for example, as a drive device for a workpiece tensioner.

Claims (11)

1. Drive device for a tool or workpiece tensioner in a spindle (1) of a machine tool, with a pressure plunger (10) arranged inside a housing (5, 6) for the drive of the tool or workpiece tensioner (2) and with a device (4) arranged in a central passage opening (21) of the housing (5, 6) for feeding a working and / or cleaning fluid to the spindle (1) of the machine tool, characterized in that in a side wall (17) of the housing (5, 6) there are provided several through holes (16) spaced apart from each other and arranged concentrically around its central axis (15), in which, by means of the pressure plunger (10), plungers (14) are housed that can be displaced axially, because the housing (5, 6) contains at least one leakage channel (22) with a section (25) that runs between the plungers diver (14) radially outward, and because the device (4) pr It has an outlet opening (39) that is in contact with the leakage channel (22). 2. Drive device according to claim 1, characterized in that the housing (5, 6) contains an inner part of the housing (5) and an outer part of the housing (6) fixedly connected with it, by means of the which the pressure space (9) is annularly limited for the pressure plunger (10). 3. Drive device according to claim 2, characterized in that the inner part of the housing (5) has a radial flange (17) that forms the side wall with the through holes (16) for the piston plungers (14). 4. Drive device according to claim 2 or 3, characterized in that the leakage channel (22) runs inside the housing (5). 5. Drive device according to claim 3 or 4, characterized in that the section (25) of the leakage channel (22) running radially outwardly is arranged in the radial flange (17). 6. Drive device according to one of claims 2 to 5, characterized in that the leakage channel (22) has a section (26) that runs radially inside the pressure space (9) parallel to the central axis ( fifteen). 7. Drive device according to one of claims 1 to 6, characterized in that a feed channel (42, 43, 44, 45) for a cleaning fluid is arranged in the housing (5, 6). 8. Drive device according to claim 7, characterized in that the feed channel (42, 43, 44, 45) contains a feed opening (42) arranged radially and a feed hole (43) running parallel to the central shaft (15) in an outer part of the housing (6) and a radial bore (45) with an oblique feed hole (44) in an inner part of the housing (5). 9. Drive device according to one of claims 1 to 8, characterized in that the diver plungers (14) arranged concentrically around the central axis (15) are spaced at the same angle. 10. Drive device according to one of claims 1 to 9, characterized in that the housing (5, 6) comprises several leakage channels (22) arranged concentrically with respect to the central axis (15) and spaced apart at the same angle. 11. Drive device according to one of claims 1 to 10, characterized in that the diver plungers (14) have lateral clamps (47) for radial insertion into corresponding "T" shaped slots (48) in the pressure plunger ( 10).